Termination arrangement for waveguide

ABSTRACT

A two-element waveguide terminator, wherein at the place where the flanged end of a waveguide is sandwiched between a flange of one terminator element and the other terminator element, there remains a hollow space between these elements. The one element is a sleeve disposed as a fitting over the waveguide end, but a hollow clearance space remains between sleeve and waveguide end. The one terminator element is provided with ducts interconnecting the two hollow spaces which are filled with a viscous elastic material, such as silicone rubber.

ll ite States Pate Spinner et a1.

1451 Apr. 4, 1972 [54] TERMINATION ARRANGEMENT FOR WAVEGUIDE [72] Invent r Georg Spinner, Mu nich; Juergen Luehring, Hannover; Guenter Ahrens, Langenhagen, all of Germany [731 Assignees: Spinner G.m.b.H., Elektrotechnische Fabrik; Kabel-und Metallwerke Gutehoifnung-shuette Aktiengesellschaft, Hannover, Germany {22] Filed: Aug. 26, 1970 [21] Appl.No.: 67,087

[30] Foreign Application Priority Data Aug. 29, 1969 Germany ..P 19 43 885.8

52 U.S. c1. ..333/98 R, 285/176, 285/297 511 1111.01. ..H01p 1/24 158 Field ofSearch ..174/19, 20,21 R, 22 R, 23 R, 174/76, 77 R, 84 R, 89; 333/95 R, 95 A, 98 R, 98 F;

[56] References Cited UNITED STATES PATENTS 2,685,459 8/1954 Panagrossi ..285/297 X 2,821,416 1/1958 Soehnlen et al... ....285/297 X 3,461,409 8/1969 Miller 1 ..333/98 R 3,535,661 10/1970 Berth et a1 ..333/98 R Primary ExaminerLaramie E. Askin Attorney-Smyth, Roston & Pavitt and Ralf H. Siegemund [57] ABSTRACT A two-element waveguide terminator, wherein at the place where the flanged end of a waveguide is sandwiched between a flange of one terminator element and the other terminator element, there remains a hollow space between these elements. The one element is a sleeve disposed as a fitting over the waveguide end, but a hollow clearance space remains between sleeve and waveguide end. The one terminator element is provided with ducts interconnecting the two hollow spaces which are filled with a viscous elastic material, such as silicone rubber.

5 Claims, 2 Drawing Figures PATENTEDAFR 4 I972 3,654, 577

4274A Alf/f TERMINATION ARRANGEMENT FOR WAVEGUIDE The present invention relates to structure to be used in connection with the interconnection of waveguides having similar or different cross sections. In particular, the invention relates to waveguide terminator structure comprised of two parts respectively fitting on the ends of waveguides and to be bolted together; the two parts are required to accommodate a flanged end of at least one of the waveguides. Therefore, employment of the particular connecting structure of the invention is predicted on the assumption that prior to assembly one or both of the particular waveguide ends to be connected are being or have been flanged.

Biparted connector elements of the variety outlined above generally are known, and here particularly, it is known to flange the waveguide ends to be connected. Rings are placed on the waveguides, in abutment to the flanges, and these rings are screwed together to obtain the connection. Connecting structure of this particular variety is usable only if the cross sections of the two waveguides are similar. A problem arises if, for example, a waveguide with elliptical cross section is to be connected to a waveguide having rectangular cross section. The known connector elements cannot be used directly, but an adaptor has to be interposed, which is to be connected to each of the wave guide ends. The adaptor provides for the transition between differently contoured cross sections, and has to be connected individually to each of the two waveguide ends.

Another disadvantage of providing connection by means of rings is to be seen in the following. Prior to connection, insulation has to be removed from the ends of the waveguides. As the connector rings have a relatively short axial extension, they will not necessarily cover all of the exposed and bared portions of the waveguide. Thus, there is danger of bending and kinking, so that one or the other of the two waveguides may be severely damaged adjacent the joint, to the point of uselessness.

The problem solved by the invention is to provide for connection of waveguides of any kind of cross section, whereby the connection has low reflection and is positively sealed and leak proof (gas tight) in case the waveguides to be interconnected are pressurized. In addition, the connection must have high mechanical strength and must be reliable in operation. Finally, the connection must be amenable to easy installation. It is, therefor, a particular object of the invention to provide connecting structure for connection to the end ofa waveguide and, possibly, for connection to or constituting part of an adaptor to obtain transition between waveguides of differing cross sections.

it is also an object of the invention to provide a new and improved waveguide terminator and connector for use in conjunction with waveguides constructed from corrugated tubing.

In accordance with a preferred embodiment of the present invention, the problems outlined above are solved by providing a two-element connecting structure in which at least one element is constructed as a flanged sleeve or fitting to be disposed on a waveguide, and being bolted or the like to the other element. The flange of the fitting abuts the flange of the waveguide, adjacent the second element. Hollow space between the two elements, essentially as defined by the thickness of the flange of the waveguide, and hollow clearance space between sleeve and waveguide, is filled with a viscous material that becomes resilient after injection, e.g., upon ouring. The one element has channels or ducts interconnecting the two hollow spaces or cavities as defined, and the channels are likewise filled with that viscous, elastic material. The filling material may, for example, be self-curing silicone rubber.

The second element may have similar construction in case waveguides to be connected have similar cross section. If these cross sections differ, the second element may also serve as adaptor. The fitting or sleeve is preferably placed onto the waveguide prior to flanging. Furthermore, the sleeve or fitting may be provided with indexing and positioning grooves or recesses for engagement by flanging equipment forming the flange in centered relation to the sleeve.

The connecting structure in accordance with the invention offers the advantage that the fitting covers the exposed portion of the waveguide and, actually, extends over insulation sheathing thereof which has not been removed. As the clearance between waveguide and fitting is filled with the viscous and elastic material, that portion of the waveguide is no longer amenable to undue bending and avoids, practically completely, any kinking or breaking. Thus, once the filler has become resilient, there is significant stress relief.

Another advantage to be seen is that all cavities and hollow spaces established adjacent the end of the waveguide are filled with the viscous and elastic material so that the conductor remains flexible in the fitting. Flexibility is a particular characteristic of a corrugated tube type waveguide. On the other hand, this particular filler contributes materially to leak proofing the terminator so as to remain gas tight. This is particularly important in case the waveguides, so interconnected, are under rather high internal gas pressure; protection against escape of gas is provided, while, on the other hand, water or water vapor may not seep into the connecting area as such water, if it could enter, would very likely provide corrosion.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the objects and features of the invention and further objects, features and advantages thereof will be better understood from the following description taken in connection with the accompanying drawings in which:

FIG. 1 illustrates a side elevation view, partially in section of a waveguide connecting structure in accordance with the preferred embodiment ofthe present invention; and

FIG. 2 illustrates a section view along lines 22 in FIG. 1.

The terminator structure illustrated in the figures is provided particularly for connecting to a waveguide comprised of corrugated tubing with round (e.g., elliptical) cross section and to serve as transition piece and adaptor for connection to a waveguide with rectangular cross section. However, it is understood that the basic features of the invention are not limited to that type of interconnection; the principles underlying the invention may readily be employed for interconnecting waveguides of any cross section. For the particular type connection it is necessary merely to provide the particular connective features to but one side of the transition structure, while the transition structure may be provided for receiving directly a waveguide with rectangular cross section, to be connected thereto in a conventional manner. As this particular part is not per se related to the invention, it will not be described in detail.

Turning now to details of the drawings, reference numerals 1 and 3, respectively, denote the two elements of the two-elemen: terminator and connecting structure. They are releasably interconnected by means of bolts 4 inserted in bores 12 (see FIG. 2). Element 3 provides for the particular transition between round and non-circular cross sections; as stated, its particular structure does not have to be described in detail.

Part 1 is essentially a sleeve which is a fitting, slipped over one end of a waveguide 20. The waveguide includes corrugated tubing 21, normally covered with insulation 22, there being possibly additional protective sheathing. The insulation has been removed near the particular end of the waveguide, but sleeve 1 does not only cover the exposed portion but extends well over waveguide portions that still have insulation 22.

There is clearance between sleeve or fitting 1 and waveguide 20, defining a cylindrical ring space 5. Fitting 1 has a flange portion 2, and it is this particular flange by means of which the first part is bolted to the second part, adaptor 3. The end of waveguide tube 21 has been flanged, to form a flange 23. That flange is sandwiched in between the elements 2 and 3 as bolted together. Due to the finite thickness of tube 21 and of flange 23, there remains a hollow space or ring-shaped cavity or chamber 6, between flange 2 on one hand and adaptor 3 on the other hand.

Hollow space 5, as well as hollow space 6, are completely filled with an initially viscous, subsequently elastic material 7. In accordance with the invention and as a specific feature of the invention, hollow spaces 5 and 6 are interconnected by means of channels or ducts 8 in the first part, extending primarily through flange 2. These ducts are likewise penetrated by the material 7. An injection port 9 traverses sleeve 1 laterally and communicates directly with ring space 5. Thus, it suffices to inject the viscous filler material through port 9, preferably under pressure, so as to fill all these interconnected hollow spaces and channels. Particularly, the injected material enters ring space 5 and spreads therein, it penetrates channels 8 and fills axial space 6 as well as any and all cavities in communication therewith. Most importantly, the injected material will fill all these spaces completely. Upon completion the port 9 is suitably plugged.

A pair of grooves 10 are provided in fitting 1, in order to aid in the distribution flow of the injected material and to facilitate flow into all portions of space S, particularly those remote from opening 9. Grooves l wrap around the circular, inner periphery of fitting 1, close to one end thereof. The injected material as particularly filling grooves 10 and after curing ensures that the cylindrical space is closed off adjacent the open end offitting I.

As one can see, particularly from FIG. 2, all channels or ducts 8 terminate in a circle at the one axial face of flange 2 that faces part 3. All these channel ends are interconnected by a circular groove 13 in flange 2. That groove provides also for uniform distribution of the material 7 as it is being injected so that, in fact, all channels and the entire hollow space 6 will be filled with that material. It should be noted that the axial dimension of space 6, as defined by the wall thickness of tubing 21, may be smaller than the depth of groove 13. Thus, the groove greatly facilitates spreading of the viscous filler in hollow space 6 oflow height.

After curing, the new resilient material provides both, stress relief and sealing. If silicone rubber is used, good bonding thereof to the metal parts contributes particularly to scaling. One can say that the resilient filler in the ring-shaped channels and 13 provides integral sealing rings, extending around the waveguide.

FIG. 1 illustrates, furthermore, that part 3 has an inlet duct 16 which leads to the interior of the waveguide, particularly into the waveguide assembly as completed by means of terminator and transition assembly 1, 2, 3. Gas may be introduced into the waveguide assembly through that duct or opening l6. After the interior of the interconnected waveguides has been pressurized, a cap screw 15 is screwed onto the stud illustrated to cover channel 16 for preventing escape and leakage of gas.

The reference numeral 11 denotes a special sealing element or gasket which seals the transition piece 3 relative to the flanged end of waveguide 20. In particular, ring 11 is disposed in a circular groove in element 3 and is urged against flange 23 upon bolting.

As was outlined above, sleeve 1 should be slipped onto the waveguide prior to forming the flange 23 of tubing 21. In accordance with an additional feature of the invention, fitting 1 may be provided with means for centering the flange formation. For example, there may be provided two indexing grooves 14 disposed in diametrical alignment and which are to be used to proceed as follows.

First, sleeve 1 is placed upon the waveguide 20 which is not yet provided with flange 23. Next, flanging equipment is positioned and indexed with the aid of grooves 14. Now, flange 23 is provided by a process operating concentric to the sleeve. This way, the flange as provided, has accuracy, size and position as needed in relation to the sleeve which, in turn, facilitates in the assembly of the entire connection.

The invention is not limited to the embodiments described above but all changes and modifications thereof not constituting departures from the spirit and scope of the invention are intended to be included.

We claim: 4 1. Termination arrangement, including a waveguide, a first element and a second element connected to the end of the waveguide, the waveguide having a flanged end;

the first element having a sleeve disposed as a fitting on the waveguide, the sleeve having one end provided with a radially extending flange, the first and second elements disposed to sandwich the flanged end of the waveguide in between the flange of the first element and the second element, there remaining a first hollow space between the flange of the first element and the second element, the two elements being secured to each other;

the sleeve portion of the first element, as receiving the waveguide near the flanged end thereof, providing a second ring space between the sleeve and the waveguide; means defining a plurality of ducts in the first element, in-

terconnecting the first and the second space; and

an initially viscous, subsequently elastic material filling the first space and the ducts.

2. Termination arrangement as in claim 1, there being a groove in the sleeve, facing the waveguide and disposed adjacent the end of sleeve which is remote from the flanged end of the sleeve.

3. Termination arrangement as in claim I, the flange of the first element having an axially directed front end, the ducts terminating in the first end, there being a groove in the front end interconnecting the ducts.

4. Termination arrangement as in claim 1, the flange of the first element bearing against the flange of the waveguide end.

5. Termination arrangement as in claim 1, the first element provided with indexing grooves for orienting equipment for flanging the waveguide. 

1. Termination arrangement, including a waveguide, a first element and a second element connected to the end of the waveguide, the waveguide having a flanged end; the first element having a sleeve disposed as a fitting on the waveguide, the sleeve having one end provided with a radially extending flange, the first and second elements disposed to sandwich the flanged end of the waveguide in between the flange of the first element and the second element, there remaining a first hollow space between the flange of the first element and the second element, the two elements being secured to each other; the sleeve portion of the first element, as receiving the waveguide near the flanged end thereof, providing a second ring space between the sleeve and the waveguide; means defining a plurality of ducts in the first element, interconnecting the first and the second space; and an initially viscous, subsequently elastic material filling the first space and the ducts.
 2. Termination arrangement as in claim 1, there being a groove in the sleeve, facing the waveguide and disposed adjacent the end of sleeve which is remote from the flanged end of the sleeve.
 3. Termination arrangement as in claim 1, the flange of the first element having an axially directed front end, the ducts terminating in the first end, there being a groove in the front end interconnecting the ducts.
 4. Termination arrangement as in claim 1, the flange of the first element bearing against the flange of the waveguide end.
 5. Termination arrangement as in claim 1, the first element provided with indexing grooves for orienting equipment for flanging the waveguide. 